A method of enhancing the coding efficiency in the conventional image coding includes a method of reducing spatial redundancy. The prediction of a target block is carried out using an adjacent coded pixel in an intra prediction coding in H.264. H.264 is disclosed in Kadono et al., “H.264/AVC text Impress standard text series”, Impress network business company, 2004, and the like.
Japanese Patent Application Laid-Open No. 2007-043651 proposes searching for a similar area from a coded region with an adjacent coded pixel as a template, and using an adjacent region at the same positional relationship as the target block as a prediction value of the target block.
Japanese Patent Application Laid-Open No. 2007-074725 proposes dividing the target block into plurals, coding and decoding one part of the divided block, and using the pixel in which one part of the block is decoded for the prediction on the remaining pixels.
Furthermore, Japanese Patent Application Laid-Open No. 2009-049969 proposes using not only the adjacent pixels between blocks but also the adjacent pixel in the target block as a prediction value to use high correlation between adjacent pixels.